In the Brihadaranyaka Upanishad we get a most illumining description of the immortal Self and its primordial state of complete union with the all-pervading Divine consciousness.
In the Unitive state there is no suffering and pleasure, there is no birth and death; there is only a state of being.
At times the Self may incarnate in a certain body and have a dream like experience in and through this particular body. However whatever may befall this particular body, it is like a mere passing experience which leaves no lasting mark on the state of being.
Thus, when we feel I am hungry or I am in pain, what we really mean is that this particular body is hungry, this body has taken on the experience of pain. In ordinary life we perceive ourselves to be in a body, with a thinking mind and human emotion. But, this is not the real Self. At this point, the immortal words of the Bhagavad Gita throw light on the difference between the material world of impermanence and the Self’s reality of absolute permanence
"Even as man discards old clothes for the new ones, so the dweller in the body, the soul, leaving aside the worn-out bodies, enters into new bodies. The soul migrates from body to body. Weapons cannot cleave it, nor fire consume it, nor water drench it, nor wind dry it." 
Furthermore, the Upanishads reveal that the nature of the Unitive state is beyond sex; it is neither male nor female, but contains the essence of both polarities in perfect harmony. Within the Self there is no concept of man made morality, good and evil do no exist. The Unitive state is in all; everything is but a dream of God, the all-pervading consciousness. To an un-illumined seeker, these concepts may be hard to grasp, for if we live in the world of duality, it is not possible to avoid such concepts. Yet, the Upanishads do not shrink from unveiling the supreme mystery of life, which is: what is the nature of God, my real Self?
"In that Unitive state one sees without seeing, for there is nothing separate from him; smells without smelling, for there is nothing separate from him; speaks without speaking, for there is nothing separate from him; knows without knowing for there is nothing separate from him." 
In the Unitive state negative emotions of anger, hate, jealousy and anxieties cannot occur. How can we be jealous of our own Self? How is it possible to hate the Self which offers only unconditional love. How is it possible to be anxious when nothing can affect the intense delight of being?
Furthermore other Upanishads tell us that the essence of this unitive state is infinite and unalloyed bliss.
"From Delight we came into existence.
In Delight we grow.
At the end of our journey’s close,
Into Delight we retire.
The intense inner ecstasy of this state of being can never be described in words. But, when we gain a glimpse of this consciousness we will never feel desire for the pleasures of this world.
 Brihadaranyaka Upanishad